#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
LL a[maxn],mp[50];
LL dp[maxn];
int main(void){
   cin.tie(0);std::ios::sync_with_stdio(false);
   LL n;cin>>n;
   for(LL i=1;i<=n;i++) {
        cin>>a[i];
        if(a[i]>0) mp[a[i]]=1;
   }
   LL ans=0;
   for(LL i=1;i<=30;i++){
       if(!mp[i]) continue;
       for(LL j=1;j<=n;j++) dp[j]=0;
       LL mx=0;
       for(LL j=1;j<=n;j++){
           if(a[j]>i) dp[j]=0;
           else{
              dp[j]=max(dp[j-1]+a[j],(LL)0);
              mx=max(mx,dp[j]);
           }
       }
       ans=max(ans,mx-i);
   }
   cout<<ans<<"\n";
   return 0;
}
